Calutron control circuit



Jan. 31, 1956 K. R. MaCKr-:NZIE ET AL 2,733,350

CALUTRON CONTROL CIRCUIT 2 Sheets-Sheet l Filed Aug. l5, 1946 .N UTYINVENToRs. /ffA/A/frf/ MAC Kf/vz/E ATTORNEY Jan. 31, 1956 K, R MacKENz|EET AL 2,733,350

CALUTRON CONTROL CIRCUIT 2 Sheets-Sheet 2 Filed Aug. l5, 1946 d ATTORNEYUnited States Patent() 2,733,350 CALUTRON CONTROL CIRCUIT Kenneth R.MacKenzie, Richmond, and William M. Brobeclr, Berkeley, Calif.,assignors to the United States of merica as represented by the UnitedStates Atomic Energy Commission Application August 15, 1946, Serial No.690,803 7 Claims. (Cl. Z50-41.9)

This invention relates to a protective arrangement for a calutron toprevent inadvertent overheating of watercooled structure of thecalutron.

A calutron is an electromagnetic An object of this invention is toprovide a calutron with apparatus for preventing the inadvertentoverheating of parent to those skilled in the art to which it thefollowing specification, claims, and drawing.

Referring to the drawing briefly,

Figure l is a schematic wiring diagram of an embodiment of thisinvention; and

Fig. 2 is a schematic wiring diagram embodying a modified form of thisinvention. Y

In order to prevent inadvertent overheating of watercooled structure ofa calutron, the water supplies associated with these structures areinterlocked with the electrical supplies which heat these structures.

In one modiiication of the invention all of the Water supplies of thecalutron are interlocked with all of the calutron 16B of the vention hasbeen applied, electrical networks. This tank 12 which is arranged 1n theair gan of an electromagnet (not shown) and by means of a vacuum pumpThe ion transmitter 15 illustrated here includes an ion source and anion accelerating electrode struc 2 ture 30. The collector 16 is providedwith two pockets 17 and 18 in which Inonoisotopically enriched materialis to be collected.

The ion source 20 comprises a charge chamber 21 and an c chamber 22communicating therewith, two corref respectively assoing bushing. Thethermioncally emissive cathode 25 Vis supported above the arc chamber bymeans of two rigid leads 28, 28 extending through and insulated fromvthe wall of the tank 12. The ion accelerating structure 30 includes twospacedapart electro es 31, 31 forming a beam dening slitV 32 duringoperationQ A C-shaped liner 40 is arranged within the tank 12, the axisof the liner 49 and the axis of the tank 12 being substantiallyparallel. One end of the liner 40 is arranged in collector 16 in whichions operating.

The leads 28, 23 of the cathode 25 supporting the source areywater-cooled supplied through a rst'rnain conduit 50 including a rstvalve 51 and a first flow switch 52 and through two branch and the arm 27 by means of water Connected to the outer ends of 27 and thence intothe water sump.

charge end ofv this section 4 3 passes out through the. wall thissection the C liner is cooled from end to end including the end adjacentthe electrode structure 30.

The collector 16 is water-cooled by means of water supplied through athird main conduit 61 comprising two serially connected sections 62 and63 ioined together by means of an insulating coupling 64. The firstsection 62 is arranged externally of the tank 12 and includes a thirdvalve 65 and a third flow switch 66. The second section 63 extendsthrough the wall of the tank 12 and is insulated therefrom and isarranged in heat exchange relation with the collector 16. The dischargeend of this section 63 likewise passes out through the wall of the tank12. When cooling water is flowing through this section the collector 16is cooled.

In the calutron illustrated here, the ion source is electricallyconnected to the wall of the tank 12 and is grounded and theaccelerating electrode structure and the C liner and the collector 16are insulated from the tank wall so that they may be maintained at ahigh negative potential with respect to ground in a manner hereinafterset forth.

In order to strike an arc in the are chamber 22 and to control it in asuitable manner electrical power is supplied to the heaters 23 and 24associated with the charge chamber 21, the arc chamber 22, and also tothe thermionically emissive cathode 25. The heating of the chargechamber 21 causes a charge of solid material previously placed thereinto vaporize and flow into the arc chamber 22 where it becomes ionizedand some of the ions formed are withdrawn through the slit 26 into thebeam defining slit 32 in the accelerating electrode structure 30 andthence projected along arcuate paths to the collector 16. Moreparticularly, the thermionically emissive cathode 25 and the twoelectrical heaters 23 and 24 and the two electrical heaters 33, 33 aresupplied power through corresponding first, second, third, and fourthpower supplies 70, 80, 90 and 100 respectively associated therewith.

The first power supply includes a manually operable switch 72, a variac74, and an isolation transformer arranged in the order named between theinput '76 and the output 78 thereof. The second power supply 80 alsocomprises a manually operable switch 82, a variac 84, and an isolationtransformer operatively connected in the order named between the input86 and the output 8S thereof. 'Ihe third power supply 90 also comprisesa manually operable switch 92, a variac 94, and an isolation transformeroperatively connected between the input 96 and the output 98 thereof.And the fourth power supply 100 likewise comprises a manually operableswitch 102, a variac 104, and an isolation transformer operativelyconnected in the order named between the input 106 and the output 108thereof.

An arc voltage supply 110 having an input 112 and an output 114 isprovided, the output of which is electrically connected between the wallof the arc chamber 22 and the cathode 25 so as to maintain the cathode2S negative with respect to the arc chamber 22 by means of a suitablevoltage of about fifty to two hundred volts.

There is also provided a regulated high voltage supply 120 having aninput 122 and an output 124 adapted to produce a high D. C. voltage ofthe order of about 10,000 to about 20,000 volts. The output 124 of thispower supply 120 is connected between the wall of the grounded arcchamber 22 and the accelerating electrode structure 30 so as to maintainthe ion source 15 at a positive potential relative to the ionaccelerating electrode structure 30.

Two filament supplies and 125 are associated with the arc voltage supply110 and the regulated high voltage supply respectively.

The inputs 76, S6, 96, and 106 of the first, second, third, and fourthpower supplies 70, 80, 90, and 100 mentioned above are all connected tothe main busses which are supplied power from the main power line 132through the contacts 134 of a relay 136. The two filament supplies 115and 125 are also connected to these busses 130 through a double polesingle throw switch 126. The input 112 of the arc voltage supply 110 isconnected to these busses 130 through an auxiliary double pole singlethrow switch 117 and the switch 126. ri`he input 122 of the regulatedhigh voltage supply 120 is connected to these busses 130 through anauxiliary double pele single throw switch 127 and the switch 126. Thecoil 137 of the relay 136 is connected across the conductors 132 of themain power line through contacts of three serially connected microswitchciernents (not shown) arranged in the three flow switches 52, 46, and 66respectively.

To complete the electrical control network associated with the calutron10 there is provided a vacuum pump control circuit 140 having an input142 and an output 144 and a magnet control circuit having an input 152and an output 154. The inputs 142 and 152 of these two circuits and 150are directly connected to the conductors 132 of the main power linethrough corresponding double pole single throw switches 147 and 157. Theoutput 144 of the vacuum pump control circuit 140 is connected to thevacuum pump 14. The output 154 of the magnet control circuit 150 isconnected to the coils (not shown) of the electromagnet in the gap ofwhich the tank 12 is mounted.

In operation, in order to effect an isotopic enrichment and a collectionof the enriched material, a charge of solid polyisotopic material isplaced in the charge chamber 21 and the ion source 15 is mounted in astandard manner within the tank 10. The switches 147 associated with avacuum pump control circuit 140 is then closed, thus energizing thevacuum pump 14 and initiating evacuation of the tank 12. After thepressure within the tank has been reduced to a suitably low value of theorder of l0JL mm. Hg, the switch 157 associated with the magnet controlcircuit 150 is energized, thereby establishing a magnetic field throughthe tank 12.

The valves 51, 45, and 65 in the three water conduits 50, 41 and 61 arethen opened. When the first valve 51 is opened, cooling water circulatesthrough the squirt tubes 28, 2i; and through the section of the conduit55 arranged on the bushing 27. When the second valve 45 is openedcooling water circulates through the section 43 of the conduit 4.1 inthermal contact with the C-shaped liner 40. When the third valve 65 isopened cooling water circulates through the section 63 of the conduit 61in thermal contact with the collector 16. When the rates of flow ofcooling water in the three conduits are thus established at ratesexceeding selected corresponding predetermined values, themicroswitc'nes (not shown) in the three flow switches 52, 46 and 66 areclosed thus completing the circuit including the coil 137, thusenergizing the relay 136. When the relay 136 is thus energized thecontacts 134 close and the busses 130 are electrically connected to theconductors 132 of the main power line, thus preparing the four powersupplies 70, 80, 90 and 100 and the arc voltage supply 110 and theregulated high voltage 120 and the filament supplies 115 and 125 foroperation. The switches 72, 02, 92, and 102 of these four power supplies70, 30, 90, and 100 are then selectively closed at will, thereby causingelectrical energy to ow to the thermionieally emissive cathode 25 andthe four heaters 23, 24, and 35, 33, the amount of heat supplied theretobeing regulated by adjustment of the corresponding variacs 74, 84, 94,and 104. The switch 126 is then closed thus energizing the iilamentsupplies 115 and 125 and the switch 117 is then closed thus establishingan electron accelerating voltage between the cathode 25 and the arcchamber 22 and causing ionizing electrons to be projected into the vaporin the arc chamber 22. When an arc of suitable strength and stability isthus established in the arc chamber 22, the switch 127 is closed, thuscausing the regulated voltage supply 120 to become energized and thusestablishing an ion accelerating field between the ion source 15 and theaccelerating electrode structure 30. When this eld has been established,some of the ions tural elements of the ca n alternative e the manner inwhich the inputs of some of the volt power supplies are connected to'thcmain More particularly,

are voltage supply 1 age supplies and 112, 76, s6, and 96er the e lirst,second and third termined rate the nncroswitch (not shown) in the secondliow switch 46 is closed, thus completing the circuit including the coil132 of the second relay 181 and thus ener iz,- ing this relay 181. Whenthis relay 181 is thus energized, the contacts 180 close and the input106 of the fourth When the above-referred to circuits have been preparedfor operation, the switches 82, 92, and 162 of the second,

' third, and fourth power supplies 86. 90, and 100 are closed powersupplies 70, 80 164) which are in tur re connected to the busses of themain pow' d relay 131. The coil 1 the conducto uctors 132 of the pcircuit 14% vand t operated in the m is closed thus ener- `25. Thevalves its are then opened.

control circuit 150 are first above described and the s gizing theiilament d through' a portion of hing 27. When the rate h theWater-cooled elethrough the sq the conduit 55 ranged on the bus therebycausing electrical energy to flow to the four heaters 23,V 24, and 33,33. The amount of heat supplied to these four heaters may be regulatedby adjustment of the'corresponding variacs 84, 94, and 104. When thevapor pressure in the arc chamber 22 is brought to a suiciently highvalue the switch 128 is closed if it is open, thereby energizing thetilamentsupplies 115 and 125. The switch 72A of the first power supply70 is then closed, thereby causing electrical energy to iiow to thethermionically emissive cathode 25. When this cathode 25 has beenbrought to a suiiiciently high temperature the switch ate paths throughthe `tank 12 to the collector 16 where monoisotopically enrichedmaterials derived from the polyisotopic charge material are separatelycollected in enveloping relationship thereto whereby said paths areelectrostatically shielded from said ion accelerating means, ion sourcecooling means including a conduit arranged in heat exchange relationshipwith said structure associated with said ion source, liner structurecooling means including a conduit arranged in heat exchange relationshipwith said liner structure, receiver cooling means including a conduitarranged in heat exchange relationship with said receiver, a voltagesupply associated with said ion accelerating means, are generating meansassociated with said ion source, and means controlled by flow of acooling medium through said three conduits at rates in excess ofcorresponding predetermined rates for preparing said are generatingmeans and said voltage supply for operation, whereby an arc may beestablished in said ion source and ions may be withdrawn therefrom andprojected along said paths only when the rates of tlow of the coolingmedium through said conduits exceed said predetermined rates.

2. In a calutron having an evacuated tank disposed in a magnetic field,an ion source and associated structure disposed in said tank, an ionreceiver disposed in said tank, an accelerating means includingelectrode structure disposed adjacent said ion source adapted totransmit selected ions from said ion source through said magnetic eldalong predetermined paths to said receiver, liner structure connected tosaid accelerating electrode structure and disposed in said tank alongsaid paths in enveloping relationship thereto whereby said paths areelectrostatically shielded from said ion accelerating means, ion sourcecooling means including a conduit arranged in heat exchange relationshipwith structure associated with said ion source, liner structure coolingmeans including a conduit arranged in heat exchange relationship withsaid liner structure, receiver cooling means including a conduitarranged in heat exchange relationship with said receiver, arcgenerating means for creating ions in said ion source, a voltage supplyassociated with said ion accelerating structure, means controlled by owof a cooling medium through said ion source cooling means at a rate inexcess of a predetermined rate for preparing said arc generating meansfor operation whereby an arc may be established in said ionsource onlywhen the rate of tlow of cooling medium through the ion source coolingmeans exceeds said predetermined rate, and means controlled by flow ofcooling medium through both said liner cooling means and said receivercooling means at rates in excess of corresponding predetermined ratesfor preparing said voltage supply or operation whereby ions may bewithdrawn from said ion source and projected along said paths only whenthe rates of ilow of the cooling medium through the conduits arranged inheat exchange relationship with said liner and with said receiver exceedsaid corresponding predetermined rates.

3. In a calutron having an evacuated tank disposed in a magnetic field,an ion source and associated structure disposed in said tank, an ionreceiver disposed in said tank, ion accelerating means includingelectrode structure disposed adjacent said ion source adapted totransmit selected ions from said ion source through said magnetic fieldalong predetermined paths to said receiver, liner structure connected tosaid accelerating electrode structure and disposed in said tank alongsaid paths in enveloping relationship thereto, whereby said paths areelectrostatically shielded from said ion accelerating means, ion sourcecooling means including a conduit arranged in heat exchange relationshipwith structure associated with said ion source, liner structure coolingmeans including a conduit arranged in heat exchange relationship withsaid liner structure, receiver cooling means including a conduitarranged in heat exchange relationship with said receiver, arcgenerating means for creating ions in said ion source, heating meansarranged in heat exchange relationship with said ion acceleratingstructure, a voltage supply associated with said ion accelerating means,means controlled by flow of a cooling medium through said ion sourcecooling means at a rate in excess of a predetermined rate for preparingsaid arc generating means for operation whereby an are may beestablished in said ion source only when the rate of iiow of coolingmedium through the ion source cooling means exceeds said predeterminedrate, means controlled by the ilow of cooling medium through said linercooling means at a rate in excess of a corresponding predetermined ratcfor preparing said heating means for operation whereby said ionaccelerating structure may be heated only when the rate of ow of coolingmedium through the conduit associated with said liner structure exceedssaid corresponding predetermined rate, and means controlled by ow ofcooling medium through both said liner cooling means and said receivercooling means at rates in excess of corresponding predetermined ratesfor preparing said voltage supply for operation, whereby ions may bewithdrawn from said ion source and projected along said paths only whenthe rates of tlow of the cooling medium through the conduits arranged inheat exchange relationship with said liner and with said receiver exceedsaid corresponding predetermined rates.

4. In a calutron having an evacuated tank disposed in a magnetic field,an ion source disposed in said tank, an ion receiver disposed in saidtank, ion accelerating means including electrode structure disposedadjacent said ion source adapted to transmit selected ions from said ionsource through said magnetic eld along predetermined paths to saidreceiver, liner structure thermally connected to said acceleratingelectrode structure and disposed in said tank along said paths inenveloping relationship thereto, whereby said paths areelectrostatically shielded from said ion accelerating means, linerstructure cooling means including a conduit arranged in heat exchangerelationship with said liner structure, heating means arranged in heatexchange relationship with said ion accelerating structure, a voltagesupply associated with said ion accelerating means, and means controlledby the flow of cooling medium through said liner cooling means at a ratein excess of a predetermined rate for preparing said heating means andsaid voltage supply for operation whereby said ion acceleratingstructure may be heated and ions may be withdrawn from said ion sourceand projected along said paths only when the rate of ilow of the coolingmedium through said conduit exceeds said predetermined rate.

5. ln a calutron having an evacuated tank disposed in a magnetic field,an ion source disposed in said tank, an ion receiver disposed in saidtank, ion accelerating means including electrode structure disposedadjacent said ion source adapted to transmit selected ions from said ionsource through said magnetic field along predetermined paths to saidreceiver, liner structure connected to said accelerating electrodestructure and disposed in said tank along said paths in envelopingrelationship thereto whereby said paths are electrostatically shieldedfrom said ion accelerating means, liner structure cooling meansincluding a conduit arranged in heat exchange relationship with saidliner structure, receiver cooling means including a conduit arranged inheat exchange relationship with said receiver, a voltage supplyassociated with said ion accelerating means, and means controlled bytlow of a cooling medium through said two conduits at rates in excess ofcorresponding predetermined rates for preparing said power supply foroperation whereby ions may be Jithdrawn from said ion source andprojected along said paths only when the rates of flow of the coolingmedium through said conduits exceed said predetermined rat` 6. In acalutron having an evacuated tank disposed in a magnetic t'ield, an ionsource disposed in said tank, an ion receiver disposed in said tank, ionaccelerating means including electrode structure disposed adjacent saidion source and adapted to transmit selected ions from source and adaptedto transmit selected ions from said ion source through said magneticfield along predeter- No references cited.

